This project's objective is to assess the fetal metabolic hemodynamic and neuropathologic effects of chronic fetal hypoxia induced by repetitive embolization of the uterine circulation. We are utilizing the chronic pregnant ewe animal model for these studies. Specific technical methodology includes both electromagnetic flow transducers and radionucleotide labelled microspheres for flow measurement. Fetal electrocortical activity is recorded directly and hormonal analyses are done by specific radioimmunoassay. Other parameters are measured by standard technique. In the ensuing year we plan to evaluate the effects of chronic fetal hypoxia on fetal organ blood flow and the regional distribution of flow within the fetal cerebral circulation. In addition we plan to examine the effects of uterine embolization on the cotyledony fetal-maternal perfusion-perfusion ratios. We also plan experiments to evaluate the effects of superimposed acute fetal hypoxia on fetal metabolism hemodynamics, brain function and neuropathology. Finally, we plan to evaluate the hormonal profile produced by embolization of the uterine circulation. These experiments should improve our understanding of the control and effectiveness of fetal and uteroplacental compensatory mechanisms under conditions of placental compromise with subsequent chronic fetal hypoxia.